The present disclosure relates generally to wireless charging coils, and more particularly to methods and systems for using wireless charging coils with a wireless charging device.
Known portable electronic devices, e.g., without limitation, smartphones, tablets, netbooks, e-readers, PDAs, and other similar devices have become increasingly prevalent in modern society. Many such electronic devices are battery powered, such as by a lithium ion battery, in order to enable the electronic device to be operated while detached from a power source. However, known battery powered devices must be periodically recharged for continuous use, because batteries lose charge during operation of the electronic device. In known systems, recharging the electronic device may include attaching the battery of the electronic device to an electrical power source through a cable or wire. In more recently known systems, a wireless charging device charges the battery using inductive coils that do not require a direct physical connection. More specifically, known wireless charging devices transmit electrical power from a charging coil in the wireless charging device to a receiving coil in the electronic device.
However, as wireless charging efficiency is at least partially related to the orientation of the charging coil with respect to the receiving coil, known wireless charging systems require the electronic device to be precisely positioned with respect to a wireless charging device. Generally wireless charging becomes more efficient as the coils are oriented parallel to each other, and charging efficiency is reduced as the coils become oriented perpendicularly to each other. Therefore, in some known systems, the wireless charging device includes shelves or slots that receive the electronic device and orient the electronic device in a particular position to enable a static charging coil to operate efficiently. In other known systems, the wireless charging device includes a flat charging pad that includes a charging coil that may be movable within an X-Y plane defined by the flat charging pad.
However, each of the known systems requires at least some predetermined positioning of the electronic device, either by placing the device into a slot, or by positioning the device on a flat charging pad. Further, known systems rapidly lose charging efficiency as the electronic device is oriented at an increasing planar angle with respect to the wireless charging device.